1. Field of the Invention
Generally, the invention relates to methods and devices for detached filtering of an operating fluid of a machine where the operating fluid is diverted from the machine, filtered and returned to the machine. More specifically, the invention relates to such methods and devices which utilize a pumping device of the machine being serviced to move the operating fluid during the detached filtering procedure.
2. Description of the Prior Art
Contaminated operating fluid is one of the leading causes of component wear and failure in most types of mechanical equipment. All equipment manufactures recommend regular cleaning or changing of operating fluid. This is particularly true where the operating fluid is a hydraulic fluid.
Operating fluids of mechanical devices routinely become contaminated during operation of the respective mechanical device. Such contamination occurs from particulate material created during normal wear of components of the mechanical device. Such contamination also often occurs from external particulate material which enters the mechanical device during operation of the mechanical device. Particulate material, if left in the operating fluid, can cause wear to various parts of the mechanical device. Contamination of operating fluids of mechanical devices also occurs from introduction of a fluid having a different composition than the respective operating fluid into the operating fluid. Many different fluids may cause such contamination of an operating fluid including operating fluids of a different composition and water.
Mechanical devices which use an operating fluids will typically have a pumping device to circulate the operating fluid during operation of the mechanical device. Often this circulation will involve movement within a transfer conduit. It is routinely known in the art to position a filter in communication with the transfer conduit. This provides for the operating fluid to be diverted from the transfer conduit and into the filter, through a filter material, and back into the transfer conduit. The filter material of the filter acts to trap at least certain particulate matter from the operating fluid and thus remove that particulate matter trapped by the filter material from the operating fluid being circulated.
Numerous methods exist to filter an operating fluid of a mechanical device. Examples of operating fluids which may be subject to filtering include hydraulic fluids, lubricating oils, drive fluids and cooling fluids.
Many varied compositions of fluids are known for use as hydraulic fluids. Such hydraulic fluids are moved through a conduit under pressure to power movement of a component. Examples of such components which are powered to move based upon the pressure of the hydraulic fluid include extending and/or retracting cylinders, motors which produce rotational output and various switches, amongst others.
Many varied compositions of fluids are known for use as lubricating oils. Many of these are based upon a petroleum derivative. Such lubricating oils are typically used to reduce friction between contacting components where movement routinely occurs between the contacting components during operation of the mechanical device.
Many varied compositions of fluids are known for use as drive fluids, such as used in automatic transmissions. Such fluids typically act as a separator between components where a first component is powered to rotate and the drive fluid transfers the rotation of the first component to a second component. This arrangement provides for the two (2) components to have different rotational speed at some particular moment while the first component's power is still transferred to the second component.
Many varied compositions of fluids are known for use as cooling fluids. Such cooling fluids typically are circulated about a machine in various conduits while extracting heat from the machine for external cooling of the fluid. Typically, the circulation of the cooling fluid will include passage through a radiator type device where heat from the cooling fluid is dispersed external from the machine. It is known to provide mechanical arrangements where hydraulic fluids, lubricating fluids and drive fluids also perform a secondary function as a medium for extraction of heat from the fluid or from the mechanical components which the fluid comes into contact with.
It is known in the art to provide periodic maintenance on mechanical devices which use an operating fluid where the operating fluid is cleaned or replaced. The most common conventionally known method for providing this periodic maintenance is referred to as changing the fluid. This procedure typically involves removing at least the majority of the existing operating fluid from the mechanical device, removing the existing filter, installing an unused filter and installing new fresh operating fluid. During this changing procedure of the operating fluid the mechanical device normally will not be operating. A drain plug often will be positioned at a lower extremity of the operating fluid containment area and is removed to allow gravity discharge of the operating fluid from the mechanical device. The drain plug is typically left out until the flow of operating fluid slows to a drip. During this period, the used filter normally is removed and replaced with a new filter. Then the drain plug is replaced and new, or reconditioned, operating fluid is installed in the mechanical device. When this process is utilized it results in some of the old operating fluid to remain in the mechanical device. Additionally, the removed used operating fluid must be discarded in some acceptable manner.
It is known to provide an operating fluid draining device having a probe and an external pump. The probe is inserted into the mechanical device, typically through a dip stick conduit, to a lower extremity of the operating fluid of the mechanical device. Then the external pump is operated to drain the operating fluid. During the maintenance operation the filter is replaced and new or reconditioned operating fluid is installed. Various of these devices provide external filtering of the operating fluid with return of the filtered operating fluid to the mechanical device. Certain of these devices are known for periodic maintenance of hydraulic fluid.
In the field of mechanical devices which utilize a hydraulic fluid to power movement of components, typically a plurality of hydraulic units will exist which may be selectively operated by an operator. These hydraulic units may perform various useful functions. Examples of such hydraulic units include cylinders which may be extended and/or retracted under power and motors which produce rotational output. A problem which exists with providing periodic maintenance on the hydraulic fluid is that hydraulic fluid resides in the hydraulic units and in conduits leading to and from them beyond valves which control the respective hydraulic units. Conventional periodic maintenance of such mechanical devices typically drain and replace the hydraulic fluid existing in the reservoir tank, leaving a quantity of old fluid within the various conduits and various hydraulic units. This produces a maintenance cycle which is less thorough than desired. Additionally, hydraulic fluid, depending upon the particular composition of the fluid, is quite expensive to replace during changing procedures. This produces considerable expensive to fleet administrators when applied to a fleet of machines or vehicles. Another issue of great concern is the transport and disposal of used and/or contaminated hydraulic fluid. Hydraulic fluid, whether new, reconditioned or used, must be handled with great care due to the significant environmental impact which may result from improper handling or improper disposal. Certain types of equipment may be deployed as a part of their respective function away from a central maintenance facility. This requires either transporting the equipment to a maintenance facility or performing the periodic maintenance ‘in the field’ where the equipment is deployed. Transport of the equipment for such periodic maintenance may involve considerable expense, considerable man hours and considerable down time for the equipment. Performing periodic maintenance ‘in the field’ where the equipment is deployed using conventionally known methods may involve considerable risk of leakage or spilling of hydraulic fluid which potentially may damage the environment. When conventional changing of the hydraulic fluid occurs ‘in the field’ clean hydraulic fluid must be transported to the site and the old used hydraulic fluid must be transported from the site. Transport of hydraulic fluids pose obvious risks including from highway accidents involving the transport vehicle. Various governmental restrictions typically exist to regulate the driver of vehicles transporting even generally small quantities, such as even a single fifty-five (55) gallon drum, of hydraulic fluid, whether new, reconditioned or used. Additionally, often special requirements exist for the transport vehicle such as display of placards indicating that the vehicle is transporting hazardous materials.
Various deficiencies exist with each of the known methods of providing periodic maintenance of operating fluids in mechanical devices. As can be seen various attempts have been made to provide ready easy periodic maintenance of operating fluids in mechanical devices. These attempts have been less efficient than desired. As such, it may be appreciated that there continues to be a need for a filtering method which filters the operating fluid of a mechanical device to a desired level of purity while utilizing the pumping device of the mechanical device with return of the filtered operating fluid to the mechanical device. This arrangement provides for a flushing of the conduits which the operating fluid typically is pumped through by the pumping device of the mechanical device. The present invention substantially fulfills these needs.